Embodiments of the present invention relate generally to dry cleaning or solvent cleaning and more particularly to solvent separation and recovery.
The process of cleaning articles with the use of solvents (also referred to as “dry cleaning”) is a well established commercial industry. Many commercial dry cleaning apparatuses incorporate a solvent recycling mechanism which enables extended use of the solvents while reducing unnecessary operator exposure to solvents. Sometimes during the dry cleaning process, the dry cleaning solvents may become mixed with small amounts of water remaining in the articles or dry cleaning machine to form an solvent phase. Before the solvent may be reused however, it is often desirable to separate and remove the water from the solvent. Failure to separate and remove water from the solvent can result in a contaminated aqueous phase that leads to bacterial growth and subsequent odor.
Typical commercial dry cleaning machines use distillation to reclaim solvent (e.g., perchloroethylene, cyclic siloxane) by first heating the solvent to the temperature at which it produces vapors. A heat exchanger collects the vapors, separates the water phase and condenses the vapors into a clean, purified solvent ready for reuse, while the impurities are concentrated in the distillate for disposal. Unfortunately, conventional distillation approaches are not practical or cost effective for dry cleaning in environments other than large commercial installations.
Although some home-based dry cleaning systems have been proposed, such systems typically only employ adsorption filters such as a carbon adsorption filter to remove impurities during a solvent recovery process. Although these adsorption filters may work well to remove some particulate matter from the aqueous phase of the solvent, they are typically not equipped to separate and remove water. Furthermore, the removal of water from the aqueous phase of the solvent can take a long time thereby increasing the necessary wash cycle time.